[@Frettzo] She looks sad. Might this be post-Amartia Astarte? :C
[@Muttonhawk] Hmm, I see your point. And to answer your question, the instant pairing part only applies to these 20 dragons that hatch from these first eggs. I made it so because I wanted to force the dragons to breed at some point, since I made so few of the at the start. Once they had hatched and started exploring the world, they would inadvertently come across some of the other 20. About the love triangles and loner possibility, maybe and yes. 

It is specified that dragons separate after their kids are of age to leave the nest, with the parents going about their business. But, while a dragon is raising a drakeling with its partner, they generally remain faithful to one another. Additionally, dragons are generally regarded as solitary beings, that doesn't mean that they won't proactively seek to mate, should they feel the urge that will come in time.

Love triangles can happen, but genetic hard-coding trumps all.